At present, more and more attention has been paid to the development of electric vehicle. As the power source of the electric vehicle, the Li-ion battery performs best charge-discharge performance and longest service life when the working temperature thereof is within 20-40 degrees. Therefore, in the prior art, a temperature control system is generally adopted to control the temperature in a battery pack.
In the prior art, a manner of connecting an electric heater and a cooling unit set in series in a circulation loop is generally adopted, the working medium in the circulation loop is heated or cooled by controlling the open-close state of the electric heater and the cooling unit set, so as to implement controlling of the temperature in the battery pack.
However, the electric heater in the prior art needs the electric power in the battery pack as power source, which will reduce the cruising distance of the electric vehicle, particularly obvious in the cold environment.